Almost nine million people, representing one in six adults in Great Britain, have not been able to buy essential food items in the past two weeks because they were not available, official research suggests. According to an Office for National Statistics (ONS) survey, 17% of adults could not buy some of the grocery products they needed between 22 September and 3 October, reflecting the widespread impact of supply chain disruption and labour shortages. Nearly a quarter of respondents (23%) told the ONS they had not been able to purchase other essential non-food items. Meanwhile, 15% reported they had not been able to buy fuel for their vehicle during the fortnight, which covered the acute phase of the fuel supply crisis in which forecourts have run dry as motorists queued for long periods to fill up their cars. The data, based on a representative sample to reflect the just over 52 million adults in Great Britain, showed the widespread impact of empty supermarket shelves. The grocery shortages appear to have been felt most strongly in the north-east and east Midlands regions, where a fifth of adults (21%) told the ONS they had not been able to buy the items they needed. Almost two-thirds of consumers surveyed (61%) reported noticing some differences in shops compared with usual, which included seeing less variety on shelves than they would expect, or not being able to find a replacement for out-of-stock items. Supply shortages also affected the availability of medicines or prescriptions, with almost a quarter (23%) of adults reporting differences compared with normal, including people having to wait longer to receive their prescription items. The newly released figures from the ONS follow weeks of reports about gaps on supermarket shelves and the closure of forecourts because of lack of fuel, and warnings about the impact on Christmas of supply chain disruption and a shortage of workers. In response, the government said on Friday that it had appointed Sir David Lewis, the former chief executive of Tesco, to be its supply chain adviser. Downing Street said Lewis would advise the prime minister on immediate improvements to UK goods supply chains, while also suggesting any necessary long-term changes. Lewis will work with officials to resolve quickly the acute, short-term issues. The supply chain and logistics industry has been saying for some time that pressures on delivery of food and goods are only likely to increase in the run-up to Christmas, which is the busiest time of the year for retailers and many other businesses.